- #1
songCalculus
- 1
- 0
Hi, I have a question about doing derivative with respect to a vector, can someone help please.
Problem:
Suppose A is a (nxn) dimensional symmetric matrix, [tex]\vec{x}[/tex] is a (nx1) column vector.
We know that
[tex]\frac{d A\vec{x}}{d \vec{x}}=A[/tex]
and
[tex]\frac{d \vec{x}^TA\vec{x}}{d \vec{x}}=2A\vec{x}[/tex] ( A is symmetric)
question:
[tex]\frac{d \vec{x}^TA}{d \vec{x}}=?[/tex]
many thanks in advance!
Problem:
Suppose A is a (nxn) dimensional symmetric matrix, [tex]\vec{x}[/tex] is a (nx1) column vector.
We know that
[tex]\frac{d A\vec{x}}{d \vec{x}}=A[/tex]
and
[tex]\frac{d \vec{x}^TA\vec{x}}{d \vec{x}}=2A\vec{x}[/tex] ( A is symmetric)
question:
[tex]\frac{d \vec{x}^TA}{d \vec{x}}=?[/tex]
many thanks in advance!
Last edited: